Field of the Invention
This invention relates to an industrial truck, in particular a lift truck, with a drive section and a load section that can be moved relative to the drive section. The load section has at least one wheelarm which is provided with at least one load roller. The load roller is rotatably mounted in a load roller carrier and the load roller carrier is swivel-mounted by a swivel bearing on the wheelarm. A bearing pin is mounted in the wheelarm for the swivel-mounting of the load roller carrier. A linkage is in an operational connection with the load roller carrier for actuation of the load roller carrier and is connected in an articulated manner with the load roller carrier by a coupling pin.
Description of Related Art
Industrial trucks with wheelarms are used to lift pallets by driving the wheelarms under a pallet and then lifting the wheelarms to lift the pallet. For this purpose, the load section is raised or lowered relative to the drive section. The load roller carriers in which the load rollers are mounted are actuated by a system of levers and a linkage and can be pivoted outwardly and downwardly or inwardly and upwardly, respectively, to raise or lower the wheelarms. On low-lift trucks or order pickers, a lifting movement of this type is called a low lift, while on high-lift trucks with an additional lifting frame it is called the initial lift.
Lift trucks of this type with load rollers located on the wheelarms in pivoting load roller carriers which are actuated by a linkage and a system of levers are described, for example, in EP 1 690 823 B1 or DE 10 2009 033 709 A1. The height of the wheelarms in the lowered position is determined essentially by the design of the swivel bearing of the load roller carrier on the wheelarm and the design of the articulated coupling of the linkage with the load roller carrier. Among other things, the diameter of the bearing pins and of the coupling pins determine the height of the wheelarms in the lowered position. Conventional lift trucks have bearing pins and coupling pins with relatively large diameters and are designed for the handling of standardized “euro pallets”, which have an entry height for the wheelarms of 100 mm. For this purpose, the trucks have a height of the wheelarms in the fully lowered position in the range of approximately 85 mm.
Because of the design of the swivel bearing of the load roller carrier on the wheelarm and the design of the articulated coupling of the linkage with the load roller carrier using relatively large-diameter bearing pins and coupling pins, it is not possible to reduce the height of the wheelarm to enable these known industrial trucks to handle special pallets, such as pallets having an entry height that is lower than on standard euro pallets.
An object of this invention is to provide an industrial truck of the general type described above but which makes possible a compact realization of the wheelarms with a low wheelarm height in the lowered position of the load section, to enable the truck to handle special pallets which have a low entry height.